1. Field of the Invention
The present invention relates to a method of manufacturing a corrugated preform and a corrugated preform, and more particularly, to a method of manufacturing a corrugated preform, which allow a concave portion and a convex portion to have substantially the same fiber volume fraction and orientation angle when a preform having a corrugated shape is manufactured based on a braiding process.
2. Description of the Related Art
In general, a vehicle body is supported by a suspension connected to tires, the suspension refers to an apparatus that absorbs vibrations and impact produced when the vehicle travels, adjusts overall balance of the vehicle body based on a state of a road surface, and prevents a tilt of the vehicle in one direction due to a centrifugal force generated when the vehicle turns in response to the centrifugal force.
In addition, a spring is included in the suspension, and specifically, a leaf spring, which is manufactured by laminating steel plates and mainly applied to a commercial vehicle such as a truck or the like, and a coil spring, which is manufactured by winding a steel wire in a coil shape and mainly applied to a passenger vehicle. The spring is typically manufactured by using a metallic material, but research is currently being conducted to substitute the metallic material with a plastic composite material to decrease deterioration caused by chipping resistibility due to corrosion, and decrease the overall weight of the vehicle.
Specifically, since the leaf spring has a simple plate shape, the substituted plastic composite material is applied to the leaf spring. However, when the material of the coil spring is substituted with the plastic composite material while maintaining the coil shape of the coil spring, it may be difficult to maintain a spring constant applied to the suspension of the vehicle due to a difference in absolute rigidity between the metallic material and the plastic composite material.
In addition, in the coil spring, the spring constant may be partially improved by increasing a diameter and a width of the wire and applying a material having greater rigidity while maintaining the coil shape, however, since there may be difficulty in applying the above spring material having high rigidity due to an increase in weight and cost, the above spring may not be applied to a mass production.
However, to substitute the metallic coil spring to which the material having substantially high rigidity is applied, research is being conducted on the spring made of the plastic composite material and having various shapes such as a wrinkle shape, a coil shape, and a wave shape, and particularly, interest is focused on a corrugated spring which is advantageous to implement a spring constant with a closed cross sectional structure.
FIG. 1 is an exemplary view illustrating a hollow corrugated spring of the related art. As illustrated in FIG. 1, the hollow corrugated spring 100 in which a concave portion 10 and a convex portion 20 are alternately laminated has a closed cross sectional structure and may be manufactured by applying a blow molding. However, since the closed cross sectional shape is manufactured by using a composite material having substantially high rigidity to implement the spring constant that can be applied to the suspension of the vehicle, the forming process may be more complex, and mass production may be difficult due to low productivity.
Moreover, since the material that may be applied to the hollow corrugated spring 100 is limited to pure thermoplastic resin or a plastic composite material which contains a reinforcing material of an amount equal to or less than a predetermined amount, and it may be possible to manufacture the entire corrugated spring using a single material, sufficient insulation performance with respect to vibration and noise may not be secured.
In addition, to maintain durability of the hollow corrugated spring 100 and a spring constant sufficient to be applied to the suspension of the vehicle, the hollow corrugated spring 100 must be manufactured based on a fiber reinforced composite material having substantially high rigidity. However, when a process such as a hand lay-up process is applied, costs may increase due to an excessive process time, it may be difficult to implement uniform deformation and physical properties due to a difference of the physical properties caused by a change of a cross sectional area, and therefore a buckling phenomenon, as illustrated in FIG. 2, may occur when the spring is deformed by a load.